<?php
use Infobird\Utils\LogUtils;
class JSSDK {
  private $appId;
  private $appSecret;
  private $redis;
  private $url;

  public function __construct($appId, $appSecret, $redis, $url) {
    $this->appId = $appId;
    $this->appSecret = $appSecret;
    $this->redis = $redis;
    $this->url = $url;
  }

  public function getSignPackage() {
    $jsapiTicket = $this->getJsApiTicket();

    // 注意 URL 一定要动态获取，不能 hardcode.
    $protocol = (!empty($_SERVER['HTTPS']) && $_SERVER['HTTPS'] !== 'off' || $_SERVER['SERVER_PORT'] == 443) ? "https://" : "http://";
    //$url = "$protocol$_SERVER[HTTP_HOST]$_SERVER[REQUEST_URI]";
    $url = $this->url;

    $timestamp = time();
    $nonceStr = $this->createNonceStr();

    // 这里参数的顺序要按照 key 值 ASCII 码升序排序
    $string = "jsapi_ticket=$jsapiTicket&noncestr=$nonceStr&timestamp=$timestamp&url=$url";

    $signature = sha1($string);
    $arr = json_decode($this->redis->get('access_token'),true);
    $access_token = $arr['access_token'];
    $signPackage = array(
      "appId"     => $this->appId,
      "nonceStr"  => $nonceStr,
      "timestamp" => $timestamp,
      "url"       => $url,
      "signature" => $signature,
      "rawString" => $string,
      "jsapiTicket" => $jsapiTicket,
      "access_token" => $access_token
    );
    return $signPackage; 
  }

  private function createNonceStr($length = 16) {
    $chars = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789";
    $str = "";
    for ($i = 0; $i < $length; $i++) {
      $str .= substr($chars, mt_rand(0, strlen($chars) - 1), 1);
    }
    return $str;
  }

  private function getJsApiTicket() {
    // jsapi_ticket 应该全局存储与更新，以下代码以写入到文件中做示例
    //$data = json_decode($this->get_php_file("jsapi_ticket.php"));
    $data = json_decode($this->redis->get("jsapi_ticket"), true);
    if (!$data || $data['expire_time'] < time()) {
      $accessToken = $this->getAccessToken();
      // 如果是企业号用以下 URL 获取 ticket
      // $url = "https://qyapi.weixin.qq.com/cgi-bin/get_jsapi_ticket?access_token=$accessToken";
      $url = "https://api.weixin.qq.com/cgi-bin/ticket/getticket?type=jsapi&access_token=$accessToken";
      $res = json_decode($this->httpGet($url));
      if(!empty($res->ticket)) {
        $ticket = $res->ticket;
        if ($ticket) {
            $data['expire_time'] = time() + 7000;
            $data['jsapi_ticket'] = $ticket;
            $this->redis->set("jsapi_ticket", json_encode($data));
        }
      }
      else {
          if(!empty($res->errcode) && $res->errcode == 40001)
          {
              $this->redis->delete('access_token');
              $accessToken = $this->getAccessToken;
              $res = json_decode($this->httpGet($url));
              if(!empty($res->ticket)) {
                $ticket = $res->ticket;
                if ($ticket) {
                    $data['expire_time'] = time() + 7000;
                    $data['jsapi_ticket'] = $ticket;
                    $this->redis->set("jsapi_ticket", json_encode($data));
                }
              }
          }
          else
            throw new Exception('get js api ticket fail! response:' . json_encode($res));
      }
    } else {
      $ticket = $data['jsapi_ticket'];
    }

    return $ticket;
  }

  private function getAccessToken() {
    // access_token 应该全局存储与更新，以下代码以写入到文件中做示例
    $data = json_decode($this->redis->get("access_token"),true);
    if (!$data || $data['expire_time'] < time()) {
      // 如果是企业号用以下URL获取access_token
      // $url = "https://qyapi.weixin.qq.com/cgi-bin/gettoken?corpid=$this->appId&corpsecret=$this->appSecret";
      $url = "https://api.weixin.qq.com/cgi-bin/token?grant_type=client_credential&appid=$this->appId&secret=$this->appSecret";
      $res = json_decode($this->httpGet($url));
      if(!empty($res->access_token)) {
        $access_token = $res->access_token;
        if ($access_token) {
            $data['expire_time'] = time() + 7000;
            $data['access_token'] = $access_token;
            $this->redis->set("access_token", json_encode($data));
        }
      }
      else {
          throw new Exception('get access token fail! response:' . json_encode($res));
      }
    } else {
      $access_token = $data['access_token'];
    }
    return $access_token;
  }

  private function httpGet($url) {
    $curl = curl_init();
    curl_setopt($curl, CURLOPT_RETURNTRANSFER, true);
    curl_setopt($curl, CURLOPT_TIMEOUT, 500);
    curl_setopt($curl, CURLOPT_SSL_VERIFYPEER, false);
    curl_setopt($curl, CURLOPT_SSL_VERIFYHOST, false);
    curl_setopt($curl, CURLOPT_URL, $url);
    $res = curl_exec($curl);
    curl_close($curl);
    return $res;
  }

  private function get_php_file($filename) {
    return trim(substr(file_get_contents($filename), 15));
  }
  private function set_php_file($filename, $content) {
    $fp = fopen($filename, "w");
    fwrite($fp, "<?php exit();?>" . $content);
    fclose($fp);
  }
}

